Agents for retarding the growth of plants and changing their habit

ABSTRACT

Sulfonium salts and a method of retarding plant growth with said sulfonium salts.

United States Patent Osieka et al.

[451 Mar. 28, 1972 AGENTS FOR RETARDING THE GROWTH OF PLANTS ANDCHANGING THEIR HABIT Inventors: Hana Osieka; Karl-Heinz Koenig, both ofLudwigshafen (Rhine); Johann Jung, Limburgehof, Pfalz; Harry Distler,Ludwigshafen (Rhine), all of Germany Assignee: Badkche Anllin-BzSoda-Fabrik Aktiengesellschatt, Ludwigshafen (Rhine), Germany ,5 I Y ,.H

Filed: Sept. 3, 1969 Appl. No.: 870,952

Related US. Application Data Division of Ser. No. 641,163, May 25, 1967,abandoned.

Foreign Application Priority Data June 1, 1966 Germany ..P 15 42 826.9

[51] Int. Cl. 011: [58] Field oISeareh ..71/98, 76

[56] References Cited UNITED STATES PATENTS 3,101,265 8/1963 Smutny etal... I .....71/98 X 3,159,682 12/1964 Baird et al. ..260/607 3,187,0086/1965 Baird et a1. .....260/327 3,235,356 2/ 1966 Herschler ..7l/98 XPrimary Examiner-James 0. Thomas, Jr. Attomey-Johnston, Root, O'Keeffe,Keil, Thompson & Shurtlefi [57] ABSTRACT Sulfonium salts and a method ofretarding plant growth with said sulfonium salts.

5 Claims, No Drawings AGENTS FOR RETARDING THE GROWTH OF PLANTS ANDCHANGING THEIR HABIT This application is a division of our copendingapplication Ser. No. 641,163, filed May 25, 1967 now abandoned.

The present invention relates to sulfonium salts, in particulartrialkylsulfonium salts whose alkyl radicals may be substituted, and toa method of retarding plant growth with said compounds.

lt is known that trimethylammonium-B-chloreothyl chloride chlorocholinechloride (CCC) may be used for reducing the growth height of plants. Thestalk length of wheat for example may be reduced with this activeingredient and lodging prevented. However the results obtainable withthis substance are not satisfactory.

One object of the invention is to provide new sulfonium salts. Anotherobject of the invention is to provide trialkylsulfonium salts whosealkyl radicals may bear substituents. A further object of the inventionis to provide sulfonium salts which regulate the growth of plants, i.e.alter the development of plants in such a way that the plants do notgrow as high as untreated plants and are not injured.

These and other objects of the invention are achieved with sulfoniumsalts having the formula CHCHR l l R R in which R and R denote hydrogenor a lower alkyl group or a phenyl, cyano, carboxy or lower carbalkoxygroup and R denotes hydrogen, a methyl radical, chlorine, bromine,

hydroxy, chloromethyl, bromomethyl or hydroxymethyl or a radical havingthe formula in which R denotes a methyl group or hydrogen or chlorine, Rand R denote hydrogen or chlorine and X denotes an anion. The plantsexhibit sturdier growth and the color of the foliage is darker.

Since the biological action of the sulfonium compounds may be determinedby the cation, X may denote any anion: chlorides, bromides, iodides,hydroxides, methosulfates, ethyl sulfates, hydrogen sulfates and p-tolylsulfonates are preferred.

In accordance with their character as salts most of the activeingredients are water-soluble substances, some of which are crystallineand some of which are oily.

The active ingredients may for example be easily prepared by alkylatingthioethers according to the following equation:

R, R and R having the meanings given above.

Sulfides in a solvent (e.g., acetone, alcohol, benzene, acetonitrile',ether, nitromethane or water), or without a solvent, are reacted with analkylating agent, e.g. methyl iodide, methyl bromide, dimethyl sulfate,diethyl sulfate or sulfonic acid esters, at atmospheric or elevatedpressure and at a temperature of from -10 to +150 C., preferably from 0to 100 C. with or without a catalyst. Epoxides also react readily withsulfides in the presence of a mineral acid. Further possibilities ofpreparing the sulfonium compounds are for example the disproportionationof thioethers or the alkylation of disulfides and oligosulfides.

The preparation of some of the compounds of this invention will now bedescribed briefly. l. ,B-Chloroethyldimethylsulfonium iodide (I) on, e

s-crncmc11 1 11 parts (by weight) of B-ehloroethylmethyl sulfidedissolved in acetone is mixed with 14.2 parts of methyl iodide. Afterbeing allowed to stand for one day at room temperature the precipitatedcrystals are suction filtered, the mother liquor is evaporated in vacuoto half its volume and further amounts of compound I are precipitatedwith ether. The crude substance which melts at about C. and is obtainedin an almost quantitative yield is recrystallized from acetone or amixture of methanol and ether and is in the form of white needles; mp 89to 91 C.

Analysis C H S I Cale. 19.02 3.99 12.7 50.24 Found 19.5 4.0 12.4 50.6

2. B-Hydroxyethyldimethylsulfonium iodide (11) 9.2 parts (by weight) ofB-hydroxyethylmethyl sulfide and 14.2 parts of methyl iodide aredissolved in acetone and allowed to stand for l to 2 days at roomtemperature; the precipitated crystals are suction filtered and furtheramounts of the compound are precipitated from the mother liquor. Thecrude compound obtained melts at 49 C.: pure white crystals with amelting point of 54 to 55 C. are obtained by recrystallization fromacetone or a mixture of methanol and ether. The yield is percent of thetheory.

Analysis C H S I Calc. 20.52 4.74 13.7 54.21 Found 20.6 4.8 13.7 54.3

3. B-Chloroethylethylmethylsulfonium iodide (III) III may be obtained inthe same way as compounds I and II by alkylating ethyl-B-chloroethylsulfide with methyl iodide. Its melting point is 92 to 93 C.(recrystallized from a mixture of acetone and ether).

Analysis C H Calc. 22.53 4.53 Found 22.6 4.6

4. B-Hydroxyethyl-n-butylmethylsulfonium iodide (IV) iodide (methanolicsolution) Analysis: C H S Cllc. 30.44 6.2 11.59 Found 30.2 6.3 l 1.2

Other active ingredients may be prepared by analogous methods, forexample:

dimethyl-B-chloroethylsulfonium chloride m.p. 143 C.

' (with decomposition) and dimethyl-fi-chloroethylsulfonium bromide m.p.139 to 140 C. (with decomposition).

The agents for regulating plant growth according to this invention maybe used assolutions, emulsions, suspensions or dusts. The form ofapplication depends entirely on the purpose for which the agents arebeing used; in any case it should ensure a fine distribution of theactive ingredient.

For the preparation of solutions to be sprayed direct, mineral oilfractions with medium to high boiling points, such as kerosene or dieseloil, coal-tar oils and oils of vegetable and animal origin, cyclichydrocarbons, such as tetrahydronaphthalene, and alkylated naphthalenesare suitable.

Aqueous formulations may be prepared from emulsion concentrates, pastesor wettable powders (spray powders) by adding water. To prepareemulsions the ingredients as such or dissolved in a solvent may behomogenized in water by means of wetting or dispersing agents.Concentrates which are suitable for dilution with water may be preparedfrom active ingredient, emulsifying or dispersing agent and possiblysolvent. Compounds having adequate basicity may be used as salts inaqueous solution even after formation of the salt.

Dusts may be prepared by mixing or grinding the active ingredients witha solid carrier.

The agents of this invention may reach the plants either through thesoil, e.g. in admixture with fertilizers, or through the leaves byspraying. There is also the possibility of the seed being treated.

The biological action of the agents according to this invention isillustrated by the following examples.

EXAMPLE 1 Wheat grains of the Heines Koga species were sown in sandyloamy soil in Neubauer vessels (i.e. glass dishes with a diameter of l1.5 cm.). Immediately following the sowing, the active ingredients weresprayed at the rate of 12 mg. per vessel on to the surface of the soilin aqueous or methanolic solution. For comparison, in addition to theuntreated control vessel, another vessel was treated with 12 mg. of theknown active ingredient chlorocholine chloride (CCC). The plants werekept in a greenhouse. After four weeks the following differences in thegrowth height of the wheat plants were observed:

Growth height of the wheat plants Active ingredient (12 mg. per vessel)in cm. relative Control (untreated) 19.1 100 chlorocholine chloride(CCC) (aqueous solution) 1 1.5 60 fl-Chloroethyldimethylsulfonium iodide(aqueous solution) 9.3 49 p-l'lydroxyethyldimethylsulfonium The abovefigures show that the sulfonium compounds reduce the growth height to agreater extent than chlorocholine chloride.

EXAMPLE 2 An experiment was carried out with rye (species Patkurersummer rye) under the conditions described in Example 1. It can be seenfrom the results in the table below that the agents according to theinvention had a stronger effect on the growth height of the plants thanCCC.

Growth height of rye plants Active ingredient (12 mg. per vessel) ,incm. relative Control (untreated) 21.7 Chlorocholine chloride (CCC)(aqueous solution) 19.0 88 B-Hydroxyethyl-n-butylmethylsulfonium iodide(methanolic solution) 17:4 I0 p-l-lydroxyethyldimethylsulfonium iodide(methanolic solution) 17.8 82 fl-Chloroethyldirnethylsufonium iodide(aqueous solution) 17.5 8!

EXAMPLE 3 A similar experiment was carried out with oats (Flamingstreuespecies) under the conditions described in Examples 1 and 2. The rate,however, was reduced to 3 mg. of active ingredient per vessel.

As can be seen from the results below, even these small quantities weresufficient to have a pronounced effect on the growth height of the oats.Used in these amounts the known active ingredient CCC had no effect onthe growth height.

Growth height of the oats plants in cm.

Active ingredient (3 mg. per vessel) relative EXAMPLE 4 Furthercompounds were tested on wheat (Opal species) as follows. Mitscherlichcontainers were filled with 6 kg. of loamy sandy soil. After the wheatseeds had been sown the surface of the soil was sprayed with the activesubstances at a rate of 9.4 mg. per container which is equivalent to 3kg. per hectare. In addition to a control container, the known growthregulator CMH (N,N-di-methyl-N-(B-chloroethyl)-hydrazonium chloride)which reduces the growth height of wheat to a particularly marked degreewas used in the test for comparison. One month later the followingresults were observed. 1

Active ingredient Growth height of wheat We claim: I

l. A process for retarding the growth of plants which comprises bringinginto contact with said plants or seeds thereof a sulfonium compound ofthe formula wherein R is chloroethyl, bromoethyl, hydroxyethyl, or

methylallyl, and X is an anion.

2. A process for retarding the growth of plants which comprises bringinginto contact with said plants B-hydroxyethyl-n-i butylmethylsulfoniumiodide.

3. A process as claimed in claim 1 wherein said sulfonium compound isB-hydroxyethyldimethylsulfonium iodide.

4. A process as claimed in claim 1 wherein said sulfonium compound is,8-chloroethyldimethylsulfonium iodide.

5. A process as claimed in claim 1 wherein said plants or seeds thereofand said sulfonium compound are brought into contact by applying saidcompound to soil containing said plants or seeds.

* i IF POWW UNITED STATES PATENT OFFXCE (5/69) m n r CER'IRMQAM OFCQRKEQilUN Patent 1 5 2 55 Dated March 28, 1972 Inn-m d Hans Osicka eta] It is certified that error appears in the above-identificd patent andthat said Letters Patent; are hereby corrected as shown below:

First page, left-hand column, seventh line, burgehof" should readburgerhoi' Column 1, line 9, "trimethy1ammonium-6-chloreothyl" shouldread trimethylammonium-g--chloroethyl Column 2, lines 50 to 52, mm C H sI should read Caz c? 2052 4.74 ll! 54.2]

Found 201) 4,8 13,7 54.3

-- Analysis 0 H s I Calc. 20 .52 4.74 15.7 54.21

Found 20.6 L8, 13.? 5

Column 6, lines 19 to 22, "5. A process as claimed in claim 1 whereinsaid plants or seeds thereof and said sulionium compound are broughtinto contact by applying said compound to soil containing said plants orseeds should read 5. A process for retarding the growth of plants whichcomprise applying to soil containing seeds of said plants a compound ofthe formula wherein R is chloroethyl, bromoethyl, hydroxyethyl, ormethylallyl, and X is an anion.

Column 6, claim 1, line 2, cancel "of seeds thereof".

QM Signed and sealed this 26th day of December 1972 (SEAL) Attest:

EDWARD M.PLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents

2. A process for retarding the growth of plants which comprises bringing into contact with said plants Beta -hydroxyethyl-n-butylmethylsulfonium iodide.
 3. A process as claimed in claim 1 wherein said sulfonium compound is Beta -hydroxyethyldimethylsulfonium iodide.
 4. A process as claimed in claim 1 wherein said sulfonium compound is Beta -chloroethyldimethylsulfonium iodide.
 5. A process as claimed in claim 1 wherein said plants or seeds thereof and said sulfonium compound are brought into contact by applying said compound to soil containing said plants or seeds. 